1. Field of the Invention
The present invention relates to a method utilized in a wireless communication and communication device thereof, and more particularly, to a method of reconfiguring parameters of a radio link control layer and parameters of related logical channels in a wireless communication system and communication device thereof
2. Description of the Prior Art
A long-term evolution (LTE) system, initiated by the third generation partnership project (3GPP), is now being regarded as a new radio interface and radio network architecture that provides a high data rate, low latency, packet optimization, and improved system capacity and coverage. In the LTE system, an evolved universal terrestrial radio access network (E-UTRAN) includes a plurality of evolved Node-Bs (eNBs) and communicates with a plurality of mobile stations, also referred as user equipments (UEs).
A radio interface protocol of the LTE system includes three layers: the Physical Layer (L1), the Data Link Layer (L2), and the Network Layer (L3), wherein a control plane of L3 is a Radio Resource Control (RRC) layer, and L2 is further divided into a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer and a Medium Access Control (MAC) layer.
The main services and functions of the RLC layer include Transfer of upper layer PDUs; Error Correction through ARQ (only for Acknowledged Mode data transfer); Concatenation, segmentation and reassembly of RLC SDUs (only for Unacknowledged Mode and Acknowledged Mode data transfer); Re-segmentation of RLC data PDUs (only for Acknowledged Mode data transfer); In sequence delivery of upper layer PDUs (only for Unacknowledged Mode and Acknowledged Mode data transfer); Duplicate detection (only for Unacknowledged Mode and Acknowledged Mode data transfer); Protocol error detection and recovery; RLC SDU discard (only for Unacknowledged Mode and Acknowledged Mode data transfer); and RLC re-establishment.
Various RLC layer parameters, such as timers and counters, are employed for the abovementioned functions/services and are configured or reconfigured by the RRC layer. In RRC (re)configuration, the RLC layer parameters are grouped into a “RLC-Config” information element (IE) that can refer to a document 3GPP TSG-RAN2 Meeting #65 R2-091971.
Logical channel are used for the RLC layer to communicate with the MAC layer. For arrangement of data priority and amount, each logical channel is configured with parameters related to transmission priority and a prioritized bit rate. Various logical channel parameters are also configured or reconfigured by the RRC layer and grouped into a “LogicalChannelConfig” IE that can refer to the document 3GPP TSG-RAN2 Meeting #65 R2-091971.
The abovementioned RLC layer parameters and logical channel parameters are considered RLC-related parameters herein. The UE starts using a reconfigured value of a RLC parameter when the RLC parameter is reconfigured by the upper layer. Furthermore, the UE may receive the “RLC-Config” or “LogicalChannelConfig” IE when the RLC-related parameters are in use. In this situation, the UE immediately uses the reconfigured value on the in-use RLC-related parameter. However, changing a value of the in-use RLC-related parameter can cause UE system failure or impacts communication system performance.
For example, a RLC counter configured with a maximum value M1 is in a counting state for a RLC procedure. During the counting of the RLC counter, the UE receives reconfiguration indicating a new maximum value M2 for the RLC counter. If M2>M1 and the UE immediately replaces M1 with M2, the RLC counter becomes being allowed to count up to M2 for the RLC procedure. Performance of the RLC procedure is affected. Improper maximum value setting can cause RLC errors.